计算参考点的E、N、U三方向
echo $lon $lat | gmt grdtrack -Gdem.grd | SAT_look your_PRM_file
计算参考点的入射角
incidence_angle = arctan2(sqrt(look_E**2 + look_N**2), look_U)
import numpy as np
# 计算向量的模
mod = np.sqrt((-0.563060)**2 + (-0.104824)**2)
# 计算反正切
incidence_angle_rad = np.arctan2(mod, 0.819741)
# 将弧度转换为度
incidence_angle_deg = np.degrees(incidence_angle_rad)
print("入射角(弧度):", incidence_angle_rad)
print("入射角(度):", incidence_angle_deg)